2-hetro substituted 4(3h)-quinazolinones

ABSTRACT

2-HETERO SUBSTITUTED 6-SULFAMOYL-7-SUBSTITUTED-4(3H)QUINAZOLINONE PRODUCTS ARE DESCRIBED. THE PRODUCTS ARE PREPARED BY CONVENTIONAL METHODS EMPLOYING THE APPROPRIATE ANTHRANILAMIDE AND THE HETERO CARBOXYLIC ACID HALIDE. THE PRODUCTS ARE XANTHINE OXIDASE INHIBITORS.

United States Patent Office Patented July 23, 1974 ABSTRACT OF THE DISCLOSURE Z-Hetero substituted 6-sulfamoyl-7-substituted-4(3H) quinazolinone products are described. The products are prepared by conventional methods employing the appropriate anthranilamide and the hetero carboxylic acid halide. The products are xanthine oxidase inhibitors.

This invention is concerned with 6-sulfamoyl-7-substituted- 4 (3'H)-quinazolinone compounds having a heterocyclic substituent attached to the 6-position carbon which 2 products have been found to exhibit marked xanthine oxidase inhibiting properties equal to or greater than exhibited by allopurinol when all compounds are evaluated in the same in vitro test.

The novel products of this invention have the structural formula A B and pharmacologically acceptable salts thereof wherein X represents halogen preferably chloro, bromo or trifluoromethyl; -R represents a heterocyclic substituent selected from pyridyl, pyrazinyl, pyrimidinyl or pyridazinyl and R represents hydrogen or C alkyl. In those compounds wherein R is hydrogen, tautomerism permits the I amide, and the like and is facilitated by heating up to the reflux temperature of the reaction mixture. When the heterocyclic acid chloride is formed in situ, the phosphorus oxychloride serves not only to form the acid chloride but as solvent as well.

Pharmacologically acceptable salts generally are the alkali metal salts or the alkaline earth metal salts. The alkali metal salts advantageously are prepared by dissolving the selected quinazolinone compound in an aqueous or alcoholic solution of the alkali metal hydroxide and if desired isolating the salt by evaporating the solvent. Any of the conventional alkali metal salts such as the sodium, potassium, lithium, or the like salts can be prepared by this method or by other methods known to organic chemists. The alkaline earth metal salts are prepared by replacement of the alkali metal by an alkaline earth metal by well known procedures.

The novel products of this invention are effective inhibitors of xanthine oxidase thus decreasing the concen- 0 tration of uric acid in the blood and urine and are effective in increasing the excretion of hypoxanthine and xanthine. The products therefore are useful in the treatment and management of gout preferably by oral administration of from about 100 to 800 mg. per day in divided doses as prescribed by the physician.

The following method was employed to prepare the products identified in Table I.

METHOD A An intimate mixture of the anthranilamide derivative (0.01 mole), the heterocycloic carboxylic acid (0.01 mole) and phosphorus oxychloride (25 ml.) is stirred at room temperature for 24 hours and then poured onto ice. The solid is collected and heated on the steam bath with ethanol ml.) and concentrated ammonium hydroxide (50 ml.) for one hour. After concentration in vacuo, the residue is treated with water (50 ml.), acidified with hydrochloric acid and the product recrystallized from a mixture of dimethylformamide and water.

TABLE I N X- NH2 x- R RCO2H POCls HzNOzS O ONHR1 H2NO2S- N-R1 Analysis Calculated Found Example M.P., number X R1 R C. Formula C H N C H N H 4-pyridyl 337 CiIlHOCINqOQS 46.36 2.69 16.63 46.52 2.70 16.67 H 4-pyrimidinyl. 323-330 ClEHBClNaOBS 42.67 2.39 20.74 42.56 2.41 20.27 CH; 4-pyridyl 263265 C14H11O1N405S 47.93 3.16 15.97 47.80 3.10 15.95 H 4-pyridazinyl 360 o zHsclNsozs 42.67 2.39 20.74 42.37 2.50 20.52 H ....de 316-317 CmHaFaNsOzS 42.05 2.17 18.86 41.93 2.35 18.5 H 2-pyrazinyl 334-336 C HsClN O3S 42.67 2.39 20.74 42.35 2.66 20.55 H 4-pyrimidinyl. 288-290 CnHsFsNsOsS 42.05 2.17 18.86 41.90 2.24 18.69 structure of the compounds to be either the keto form, Representative 3-hetero-6-sulfamoyl 7 substitutedstructure A, or the enol form, structure B. For convenience the compounds hereinafter will be identified as ketones but it is to be understood that in compounds acid. When the acid chloride is preformed, the reaction advantageously is conducted in the presence of an inert solvent such as dioxane, tetrahydrofuran, dimethylform- 4-(3H)-quinazolinone products were found to be effective when tested by an art-recognized procedure designated to evaluate xanthine oxidase inhibiting properties of compounds. The procedure used employed the principles described in J. Pharm. Sci. 562955 (1967), Baker et' al. and was carried out in the following manner:

A reference cuvette is filled with 0.05M pH 7.4 buffer. For the control, mix quickly in a cuvette 2 ml. hypoxanthine solution 6- 10- M), 2 ml. 0.05M pH 7.4 buffer solution, and 2 m1. xanthine oxidase solution, and immediately record the absorbance at 292 for one minute. For the test solution, add quickly to a separate cuvette 2 m1. hypoxanthine solution (6 10 M), 2 ml. test solution, and 2 ml. xanthine oxidase solution, and immediately record the absorbance at 292;; for one 3 minute. If the inhibition is less than 100%, the percent inhibition is calculated as follows:

AA control-AA test AA control oxidase inhibiting agent, elfects 50% inhibition of xanthine oxidase by this protocol.

TABLE II Xanthine oxidase Percent Example number of test compound inhibition Concentration 50 4X10-7M s4 2X10- M 40 2X10- M 51 2X10- M 54 2X10- M 19 2X10- M 26 2X10- M I claim: 1. A quinazolinone compound having the structural formula X l-R N-R HzNOzS \C/ and pharmacologically acceptable salts thereof wherein X represents chloro, bromo or tri fluoromethyl; R represents hydrogen and C alkyl and R represents 2,3-, or

4 4 pyridyl, 2 or 3-pyrazinyl, 2-, 5- or 6 pyrimidinyl and 3-, 4- or 5-pyrid'azinyl.

2. A product as claimed in Claim 1 wherein X is chloro.

5 3. A product as claimed in Claim 1 wherein R is hydrogen.

4. The product as claimed in Claim 1 wherein X is chloro, R is 4-pyridyl and R is hydrogen.

5. The product as claimed in Claim 1 wherein X is 10 chloro, R is 4-pyrimidinyl and R is hydrogen.

6. The product as claimed in Claim 1 wherein X is chloro, R is 4-pyridazinyl and R is hydrogen.

7. The product as claimed in Claim 1 wherein X is tr'ifluoromet-hyl, R is 4-pyridazinyl and R is hydrogen.

8. The product as claimed in Claim 1 wherein X is trifluoromethyl, R is 4-pyrimid'inyl and R is hydrogen.

References Cited 'Shetty et al.: Chemical Abstract 732771910 (1970).

DONALD G. DAUS, Primary Examiner 35 R. D. MCCLOUD, Assistant Examiner US. Cl. XJR.

260-250 R, 250 A, 2 51 Q, 556 B; 4241 

